Matter Transformation Capability Of Primary Producer And Their Relation To The Environment Factors In The Changjiang Estuary

Based on the historical investigating data in the Changjiang Estuary, the relationships between phytoplankton community construction, primary production and environmental factors were analyzed, using multi-dimensional statistical analysis methods such as Cluster, MDS, CCA, RDA et al. The results showed the seasonal variation of phytoplankton community structure was mainly caused by temperature, salinity, transparence and nutrients, and temperature was principal factor. The nutrients were the most important factors which resulted in the temporal variation of the phytoplankton community construction between the same seasons. Different types of phytoplankton species had different ways in responding to the environment variables.The amount of particulate organic carbon in phytoplankton cells was measured using transformed form of cell volume, and the connection between phytoplankton carbon production and the environmental condition was discussed in the Changjiang Estuary. The results showed salinity, transparence and nutrients (nitrogen and phosphorus) were the essential factors that restricted the distribution of phytoplankton carbon content in the Changjiang Estuary.The capability transforming matter of the predominant taxon Skeletonema costatum was examined in laboratory, and the relationship models between growth rate, chlorophyll-a and particulate organic carbon content and environmental variables were obtained. The analysis results showed that temperature, salinity and light intensity had the significant interactions in the growth rate, content of chlorophyll-a and particulate organic carbon.